Improvement in steam-engines



2 Sheets-Sheet 1.

D. TURNER. Steam-Engine.

ggfc e nted Apr-1123,1878.

N.PEERS. PHOTO-UTHDGRAPHER WASHXNGTON u c 2 Sheets Sheet 2v D. TURNER.Steam-Engine.

No. 202,894. Patented April 23, 1878. 1 4 .5.

N. PETERS. PHOTILUTHOGRAPHER. WASHINGTON D c,

UNITED STATES PATENT OFFICE DEMETRIUS TURNER, OF GRAND RAPIDS, MICHIGAN.

LI'M PROVEM ENT IN STEAM -ENGIN ES.

Specification forming part of Letters Patent No. 202,894., dated April23, 1678; application filed December S, 1877 To all whom "it mayconcern.-

Be it known that I, DEM'ETRIUS TURNER, of Grand Rapids, in the county ofKent and State of Michigan, have invented certain new and usefulImprovements in Steam-Engines; and I do hereby declare that thefollowing specification, taken in connection with the drawingsfurnished, and forming a part thereof, is a clear, true, and completedescription of my invention.

My said improvements relate to valve-gear, both for induction andexhaust.

One feature of my invention relates to gear for operating suchinduction-valves as are provided with closing springs, or, as in case ofdouble poppet-valves, have the usual unbalanced steam-pressu-re in theclosing direction, and which may be opened through the intermittentoperation of a rock-shaft; and this portion of my invention consists inthe combination, with an induction-Valve, of a rock-shaft actuated fromthe crank-shaft, a spring-bolt mounted on the rock-shaft for enablingsaid shaft to open the valve, and a segmental cam which controls thebolt in permitting it to open the valve, and also in tripping it forallowing the valve to close. This combination affords a simple,effective, and durable drop for induction-valves. The cam is capable ofadjustment, and it is also combined with a governor; and thesefeatures,-in combination with the rock-shaft and spring-bolt, constituteportions of my invention.

For enabling the rockshaft, through its spring-bolt, to communicate aslow initial opening movement to the valve, I employ an intermediate camor toe between the springbolt and valve; and in this connection myinvention further consist-s in the combination, with the rock-shaft, itsspring-bolt, and segmental cam, of a toe axially mounted on therock-shaft, which, when vibrated by the sprin gbolt and rock-shaft,lifts the valve with a gradually-increasing speed, due to the outline ofthe cam-surface, which engages with the valve-rod or devices connectedwith and practically forming a part of said rod.

For preventing the operative end of the toe from dropping too far whenreleased by the spring-bolt, I employ a stop-hook on the valve rodconnection, with which the toe engages;

and such a hook, in combination with the toe spring-bolt, cam, androck-shaft, constitutes another feature of my invention.

For operating the exhaust-valve by the rockshaft, I employ, as anotherfeature of my invention, a cam or toe, which is mounted between twoflanges axially secured to the shaft, and which is adjustable on saidflanges. This construction afl'ords a simple, efi'ective, and durablemeans for operating the exhaustvalves of an engine. The toe being easilydetachable admits of its being gradually fitted during trial of theengine, and accurately adjusted after fitting, and it is attached to therockshaft with the expenditure of but little time and labor. Moreover,the toe, being of small size, can be made of cast-steel and readilyhardened.

To more particularly describe my invention,

I will refer to the accompanying drawings, in which Figure 1 represents,in perspective, a steamchest containing one induction and one exhaustvalve with their valve-gear, the whole being adapted for connection withone end of a steam-engine cylinder, it being understood that a duplicatethereof is required for connection with the opposite end of thecylinder. Fig. 2 represents the steam-chest and both valves in verticalcentral section. Fig. 3 represents the same in horizontal centralsection. Fig. 4 represents, in perspective, the rockshaft detached. Fig.5 represents, in end and side view, the spring-bolt, segmental cam, andflange detached from the rock-shaft. Fig. 6 represents, in end and inside view, the segmental cam detached from the spring-bolt androck-shaft. Fig. 7 represents the toe detached from the rock-shaft, witha portion of the valve-bar resting thereon, and provided with astop-hook. Fig. 8 represents the spring-bolt detached. Fig. 9 representsa portion of the exhaust-valve bar, the toe which operates theexhaust-valve, and one of the flanges to which the toe is attached.

The steam-chest A is one of two which are mounted on and attached,respectively, to opposite ends of a steamengine cylinder, (not shown,)and it communicates with said cylinder through port A, both for theinduction of steam from steam-pipe B, and for exhaust by way of pipe C.The induction-valve l) and exhaust-valve E are double or balancedpoppetvalves, provided with valve-rods I) and E, respectively.

The cylindrical shell 1 within the steamchest is, as heretofore,isolated or detached therefrom, except at one side, in which there is aport, a, connecting the interior of the shell with the central portionof the steamchest, and communicating thence via port A with theengine-cylinder, as clearly illustrated in Figs. 2 and 3. The upper andlower ends of this shell are open, and provided with valveseats b forthe two plates 0 of the poppet-valve. One of these cylindrical shells isshown with the induction and onewith the exhaust valve. Both shells arefree to expand or contract, neither being in any manner obstructed inthat respect, except at the portions connecting with the steam-chest andsurrounding the ports a but these connecting portions constitute sosmall a proportion of the bulk of the shells as to not materially affecttheir uniform expansion and contraction.

In the drawings, the valve-rods l) and 1' are shown to be provided withbars 1) and E respectively; but these bars are well-known appendages to.valve-rods, and constitute no portion of my invention. Each bar ispivoted to its standard d, and may be provided with a retractile spring,01, for accelerating the closing of the valve, which would, however,take place without the spring if the upper valve 0 be larger than thelower.

\Vhile the poppet-valve is preferred by me, other forms of valve may beused in connection with the novel valve-gear hereinafter described,provided the valve used has a closing spring and a lever, with which thevalve-opening devices may engage.

The induction-valve l) is provided with a dash-pot, e, or itsequivalent, the plunger of which is attached to the outer end ofvalvebar D As the valve-bars are merely means of connection between thevalve-rods and the mechanism by which the valves are lifted, 1 proposeto employ at times other forms of connection equally well known-as forinstance, a yoke on the valve-rod, within which the lifting mechanism islocated, in which case a spring encircling the rod might be employed,and the dash-pot be located above the yoke, all in a manner well known,and not in any way aflecting the operation of the parts or the value ofmy improvements.

The valves are operated by the rock-shaft G, which derives its motionthrough suitable connections with the crank-shaft, as by an eccentric,as shown in the drawings, but which is not in the position which itwould occupy on an engine.

The rock-shaft is provided with two pairs of flanges secured thereto,with space between ltJheir inner faces sufticient to receive a valve-The induction-valve is lifted by a springbolt, f, which is housed in asleeve, h, projecting laterally from flange g, and parallel with therock-shaft, the outer end of the bolt projecting through said flangeinto the space between flanges g and g. The spring-bolt f within thesleeve is longitudinally slotted, as shown in Fig. 8, and the sleeve isprovided with a coincident but longer slot, 1'.

H denotes a segmental cam (shown in Fig. 6) provided with an inclinedsurface at one edge, as at 7:. This cam is the segment of a circle ofwhich the axis of the crank-shaft is the center, and it occupies theslots in the spring-bolt f and sleeve h.

The inclined cam-surface at k, by contact with the end of the slot inthe spring-bolt, causes the latter to move longitudinally and withdrawits head from the face of flange g, and on the reverse movement of therock-shaft the bolt is free to return to its protruded position as soonas it passes the inclined surface.

It is obvious that the inclined surface at k can be so far advanced bythe movement of the segmental cam that the spring-bolt will in no mannerbe effected by it, and it is equally obvious that the cam may be movedin the opposite direction so far as to retain the bolt wholly within thesleeve, and so prevent the valve from being opened.

The segmental cam is secured at each end to a hub, I, loosely mounted onthe rock-shaft.

When arranged for a permanent or fixed cut-off, the cam is madestationary by means of a standard bolted to the top of the steamchest,and it may be accurately adapted to cut off at a certain point in thestroke, or it may be made adjustable by means of elongated bolt-holes,so that it may be advanced or withdrawn, when the engine is at rest, byloosening the bolts.

The segmental cam is provided with the pendent arm m, which is looselyfitted to the hub l of the segmental cam, and is adjustable thereon bymeans of a set-screw.

A governor may be attached to the arm m in a manner well known, forefl'ecting an automatic variable cut-ofi". In the drawing it is shown tobe provided with a hand-governor, n, which consists of a hand wheelaxially tapped, and a screw-rod which connects with the pendent arm m,so that the segmental cam may be readily adjusted while the engine is inmotion, to cut ofi at various points in the stroke of the piston, or soset that steam will be admitted to the cylinder to the fullest possibleextent.

It will be seen that the spring-bolt may be arranged to en gage directlywith the valve-bar in operating as a valve-opening device, and that thesegmental cam will cause the bolt to he tripped at any predeterminedpoint, and allow the valve to close, and. the combination of theseparts, which admit of such an arrange ment, constitutes one portion ofmy invention. It is, however, important that the initial openingmovement of the valve should be slower than the movement of therock-shaft and bolt,

and I therefore modify the action of the rockshaft by introducingbetween the bolt and the valve a cam or toe, 0, Fig. 7, which is axiallybut loosely mounted on the rock-shaft between the flanges g g. Thecam-surface of this cam, which engages with the lower edge of thevalve-bar, may be shaped so as to vary to any desired extent the speedof the lift of the valve; but I prefer that it be opened with agradually-increased speed until tripped, or until fully opened.

When released by the tripping of the springbolt the working end of thecam is liable to be so far depressed as to throw its opposite end abovethe bolt, and in order to limit its free movement I provide a stop-hook,p, with which the toe engages after being released. This stop-hook, inthis instance, is formed on the valve-bar; but it is immaterial whetherit be a moving device or a stationary one, provided that it affords asurface on which the cam may strike after being released, and providedit be so located as to secure the proper limitation of movement.

It will be seen that the segmental cam, spring-bolt, and rock-shaftcontrol the movements of the valve with reference to time, and that thecam permits, by the peculiar shape of its working-surface, an extensivevariation of the character or quality of the valve movement.

The operation of the exhaust-valve is as heretofore, and my improvementsin thatconnection do not relate to any novel mode of operation, but tothe peculiar combination,with a rock-shaft and flanges, of a camattached thereto and adjustable thereon. The flanges are shown at q q,secured by set-screws to the rock-shaft, with space between theircoincident faces sufficient to receive the valve-bar. The cam 1 has acurved slot for the passage of bolts from one flange through to theother, and this admits of its ready adjustment, with relation to thevalve-bar, for determining the time at which the valve shall be openedand closed. The shape of the cam is more or less modified in fittingduring the trial of each engine, and this cam, being readily applied anddetached, can be fitted with but little trouble and expense, and, beingof small bulk, it can be made of cast-steel and readily hardened; andthe same is true of the cam-lever employed with the induction-valve. Sofar as my knowledge extends, this cam may be correctly placed withrelation to the flanges, rock-shaft, and valve with less expense andlabor than can such devices as have heretofore been employed in asimilar connection.

The induction and exhaust valves at the opposite end of the engine-cylinder are provided with a duplicate rock-shaft and appendages,which are connected with the one shown by means of a rod and the pendentarm 8 on the rock-shaft.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination, with an induction-val ve, of arock-shaft actuated from the crank-shaft, a spring-bolt mounted 011 saidshaft for opening the valve, and a segmental cam which controls saidbolt in permitting it to open the valve, and also in tripping the boltfor allowing the valve to close, substantially as described.

2. The combination, with an induction-valve, of a rock-shaft, aspring-bolt mounted there on, and an adjustable segmental cam,substantially as described.

3. The combination, with an induction-valve, of a rock-shaft, aspring-bolt mounted thereon, and a segmental cam which controls thespring-bolt, and is itself controlled by a governor, substantially asdescribed.

4. The combination, with an induction-valve, of a rock-shaft, aspring-bolt mounted thereon, a segmental cam for controlling the bolt,and a cam-lever which at one end lifts the valve on being depressed atthe opposite end by the spring-bolt and rock-shaft, substantially asdescribed.

5. The combination, with an induction-valve, of a rock-shaft, aspring-bolt mounted thereon, a cam for controlling the bolt, a cam ortoe axially mounted on the rock-shaft, and a stop for limiting the freemovement of the toe when released by the bolt, substantially asdescribed.

6. The combination, with an exhaust-valve, of a rock-shaft, providedwith flanges and a toe for opening and closing the valve, which isadjustably mounted between the flanges, substantially as described.

DEMETRIUS TURNER.

Witnesses:

WILLIAM AsHLEY, GEORGE F. HI'rcHoooK, Jr.

